package com.niit.mall.common.utils;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Arrays;
import java.util.Random;

/**
 * @BelongsProject: pardo_mall_backend
 * @BelongsPackage: com.niit.mall.common.utils
 * @Author: ChuXuan
 * @CreateTime: 2025-06-11  15:23
 * @Description: TODO
 * @Version: 1.0
 */
/**
 * 生成验证码工具类
 */
public class CheckCodeUtil {
	
	public static final String VERIFY_CODES = "123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
	private static Random random = new Random();
	
	
	public static void main(String[] args) throws IOException {
		OutputStream fos = new FileOutputStream("d://code.jpg");
		String checkCode = CheckCodeUtil.outputVerifyImage(100, 50, fos, 4);
		System.out.println(checkCode);
	}
	
	
	/**
	 * 输出随机验证码图片流,并返回验证码值（一般传入输出流，响应response页面端，Web项目用的较多）
	 *
	 * @param width 图片宽度
	 * @param height 图片高度
	 * @param os  输出流
	 * @param verifySize 数据长度
	 * @return 验证码数据
	 * @throws IOException
	 */
	public static String outputVerifyImage(int width, int height, OutputStream os, int verifySize) throws IOException {
		String verifyCode = generateVerifyCode(verifySize);
		outputImage(width, height, os, verifyCode);
		return verifyCode;
	}
	
	/**
	 * 使用系统默认字符源生成验证码
	 *
	 * @param verifySize 验证码长度
	 * @return
	 */
	public static String generateVerifyCode(int verifySize) {
		return generateVerifyCode(verifySize, VERIFY_CODES);
	}
	
	/**
	 * 使用指定源生成验证码
	 *
	 * @param verifySize 验证码长度
	 * @param sources    验证码字符源
	 * @return
	 */
	public static String generateVerifyCode(int verifySize, String sources) {
		// 未设定展示源的字码，赋默认值大写字母+数字
		if (sources == null || sources.length() == 0) {
			sources = VERIFY_CODES;
		}
		int codesLen = sources.length();
		Random rand = new Random(System.currentTimeMillis());
		StringBuilder verifyCode = new StringBuilder(verifySize);
		for (int i = 0; i < verifySize; i++) {
			verifyCode.append(sources.charAt(rand.nextInt(codesLen - 1)));
		}
		return verifyCode.toString();
	}
	
	/**
	 * 生成随机验证码文件,并返回验证码值 (生成图片形式，用的较少)
	 *
	 * @param w
	 * @param h
	 * @param outputFile
	 * @param verifySize
	 * @return
	 * @throws IOException
	 */
	public static String outputVerifyImage(int w, int h, File outputFile, int verifySize) throws IOException {
		String verifyCode = generateVerifyCode(verifySize);
		outputImage(w, h, outputFile, verifyCode);
		return verifyCode;
	}
	
	
	
	/**
	 * 生成指定验证码图像文件
	 *
	 * @param w
	 * @param h
	 * @param outputFile
	 * @param code
	 * @throws IOException
	 */
	public static void outputImage(int w, int h, File outputFile, String code) throws IOException {
		if (outputFile == null) {
			return;
		}
		File dir = outputFile.getParentFile();
		//文件不存在
		if (!dir.exists()) {
			//创建
			dir.mkdirs();
		}
		try {
			outputFile.createNewFile();
			FileOutputStream fos = new FileOutputStream(outputFile);
			outputImage(w, h, fos, code);
			fos.close();
		} catch (IOException e) {
			throw e;
		}
	}
	
	/**
	 * 输出指定验证码图片流
	 *
	 * @param w
	 * @param h
	 * @param os
	 * @param code
	 * @throws IOException
	 */
	public static void outputImage(int w, int h, OutputStream os, String code) throws IOException {
		int verifySize = code.length();
		BufferedImage image = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
		Random rand = new Random();
		Graphics2D g2 = image.createGraphics();
		g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
		
		// 创建颜色集合，使用java.awt包下的类
		Color[] colors = new Color[5];
		Color[] colorSpaces = new Color[]{Color.WHITE, Color.CYAN,
				Color.GRAY, Color.LIGHT_GRAY, Color.MAGENTA, Color.ORANGE,
				Color.PINK, Color.YELLOW};
		float[] fractions = new float[colors.length];
		for (int i = 0; i < colors.length; i++) {
			colors[i] = colorSpaces[rand.nextInt(colorSpaces.length)];
			fractions[i] = rand.nextFloat();
		}
		Arrays.sort(fractions);
		// 设置边框色
		g2.setColor(Color.GRAY);
		g2.fillRect(0, 0, w, h);
		
		Color c = getRandColor(200, 250);
		// 设置背景色
		g2.setColor(c);
		g2.fillRect(0, 2, w, h - 4);
		
		// 绘制干扰线
		Random random = new Random();
		// 设置线条的颜色
		g2.setColor(getRandColor(160, 200));
		for (int i = 0; i < 20; i++) {
			int x = random.nextInt(w - 1);
			int y = random.nextInt(h - 1);
			int xl = random.nextInt(6) + 1;
			int yl = random.nextInt(12) + 1;
			g2.drawLine(x, y, x + xl + 40, y + yl + 20);
		}
		
		// 添加噪点
		// 噪声率
		float yawpRate = 0.05f;
		int area = (int) (yawpRate * w * h);
		for (int i = 0; i < area; i++) {
			int x = random.nextInt(w);
			int y = random.nextInt(h);
			// 获取随机颜色
			int rgb = getRandomIntColor();
			image.setRGB(x, y, rgb);
		}
		// 添加图片扭曲
		shear(g2, w, h, c);
		
		g2.setColor(getRandColor(100, 160));
		int fontSize = h - 4;
		Font font = new Font("Algerian", Font.ITALIC, fontSize);
		g2.setFont(font);
		char[] chars = code.toCharArray();
		for (int i = 0; i < verifySize; i++) {
			AffineTransform affine = new AffineTransform();
			affine.setToRotation(Math.PI / 4 * rand.nextDouble() * (rand.nextBoolean() ? 1 : -1), (w / verifySize) * i + fontSize / 2, h / 2);
			g2.setTransform(affine);
			g2.drawChars(chars, i, 1, ((w - 10) / verifySize) * i + 5, h / 2 + fontSize / 2 - 10);
		}
		
		g2.dispose();
		ImageIO.write(image, "jpg", os);
	}
	
	/**
	 * 随机颜色
	 *
	 * @param fc
	 * @param bc
	 * @return
	 */
	private static Color getRandColor(int fc, int bc) {
		if (fc > 255) {
			fc = 255;
		}
		if (bc > 255) {
			bc = 255;
		}
		int r = fc + random.nextInt(bc - fc);
		int g = fc + random.nextInt(bc - fc);
		int b = fc + random.nextInt(bc - fc);
		return new Color(r, g, b);
	}
	
	private static int getRandomIntColor() {
		int[] rgb = getRandomRgb();
		int color = 0;
		for (int c : rgb) {
			color = color << 8;
			color = color | c;
		}
		return color;
	}
	
	private static int[] getRandomRgb() {
		int[] rgb = new int[3];
		for (int i = 0; i < 3; i++) {
			rgb[i] = random.nextInt(255);
		}
		return rgb;
	}
	
	private static void shear(Graphics g, int w1, int h1, Color color) {
		shearX(g, w1, h1, color);
		shearY(g, w1, h1, color);
	}
	
	private static void shearX(Graphics g, int w1, int h1, Color color) {
		
		int period = random.nextInt(2);
		
		boolean borderGap = true;
		int frames = 1;
		int phase = random.nextInt(2);
		
		for (int i = 0; i < h1; i++) {
			double d = (double) (period >> 1)
					           * Math.sin((double) i / (double) period
							                      + (6.2831853071795862D * (double) phase)
									                        / (double) frames);
			g.copyArea(0, i, w1, 1, (int) d, 0);
			if (borderGap) {
				g.setColor(color);
				g.drawLine((int) d, i, 0, i);
				g.drawLine((int) d + w1, i, w1, i);
			}
		}
		
	}
	
	private static void shearY(Graphics g, int w1, int h1, Color color) {
		
		int period = random.nextInt(40) + 10; // 50;
		
		boolean borderGap = true;
		int frames = 20;
		int phase = 7;
		for (int i = 0; i < w1; i++) {
			double d = (double) (period >> 1)
					           * Math.sin((double) i / (double) period
							                      + (6.2831853071795862D * (double) phase)
									                        / (double) frames);
			g.copyArea(i, 0, 1, h1, 0, (int) d);
			if (borderGap) {
				g.setColor(color);
				g.drawLine(i, (int) d, i, 0);
				g.drawLine(i, (int) d + h1, i, h1);
			}
			
		}
		
	}
}
